Shortcut distillation

[Flaming]

Hi all,

I have the follow components with their respective boiling points and I wish to separate it using shortcut distillation, my desired product is Acetaldehyde. May I know what is the light key and the heavy key? I'm using NRTL as the fluid package

Acetaldehyde 20.2
Ethyl acetate 77.1
Crontoaldehyde 104
Butyraldehyde 74.8
Acetone 56.5
HCHO -19
Ethanol 78.37
Water 100
Hydrogen -252.87

I assigned Acetaldehyde as the LK and Butyraldehyde as HK, but it seems to give me error

[irma reyes martinez]

the best selecction is ligth key acetaldehyde and athe heavy key ethil acetate, if you want take crotonaldehyde the calculation es very hard, you can see the mass transfer operation of treybal if you want take the heavy key crotonaldehyde